Value of type '<typename1>' cannot be converted to '<typename2>' (Multiple file references)
In a situation where a project makes more than one file reference to an assembly, the compiler cannot guarantee that one type can be converted to another.
Each file reference specifies a file path and name for the output file of a project (typically a DLL file). The compiler cannot guarantee that the output files come from the same source, or that they represent the same version of the same assembly. Therefore, it cannot guarantee that the types in the different references are the same type, or even that one can be converted to the other.
You can use a single file reference if you know that the referenced assemblies have the same assembly identity. The assembly identity includes the assembly's name, version, public key if any, and culture. This information uniquely identifies the assembly.
Error ID: BC30961
To correct this error
If the referenced assemblies have the same assembly identity, then remove or replace one of the file references so that there is only a single file reference.
If the referenced assemblies do not have the same assembly identity, then change your code so that it does not attempt to convert a type in one to a type in the other.